Risk Factors Associated with Mastitis Occurrence in Dairy Herds in Benisuef, Egypt

Abstract

A cross sectional study was carried out from April, 2009 till the end of November, 2011 to estimate prevalence of mastitis and its risk indicators in private dairy herd in Beni-suef region. A total of 233 Holstein milking cows were tested using California Mastitis Test (CMT). Prevalence of mastitis at cow level was 42.92 % (100/233), out of which 9.87% (23/233) and 33.05% (77/233) were clinical and subclinical mastitis, respectively. The quarter level prevalence was 29.08 (272/929); from this the clinical and subclinical forms were 5.81 (54/929) and 23.47 % (218/929), respectively. Samples from all 54 active clinical cases and 98.0% (208/211) of positive CMT subclinical quarters were found to be culture positive. A total of 272 bacteria were isolated, the most prevalent being coagulase negative Staphylococcus (CNS; 37.8%), S. aureus (25.8%) followed by E.coli (18.7 %). Other bacterial isolates included Streptoccusagalactiae (11.8 %), Klebsiellapneumonae (3.6 %) and Str.uberis (2.8 %). Risk factors such as age difference, stage of lactation, parity, tick infestation, previous history of clinical mastitis, and farm hygiene were highly significant in the mastitis prevalence (P < 0.01). On the other hand, strong relationship was found between milk production and occurrence of bovine mastitis as, prevalence was higher in adult cows (X 2 = 9.50, P< 0.05), hence the risk of developing mastitis significantly increase (P< 0.003) in lactating cow at ages (3-5 years) , at early lactation stage , with paritynumber (2-4) and during summer months, than those corresponding animals. In conclusion, the potential risk factors associated with mastitis prevalence and severity includes cow's itself and their surrounding environment particularly farm and milking hygiene procedure. Moreover, veterinary supervision, and tick infestation are among the potential risk factors predispose and increase severity of mastitis problem in dairy farm.